GEORGE CLOONEY, star of the new Second World War art theft film The Monuments Men, on the lessons he's learned from fame, how his father keeps him in check and his disdain for social media...

MONUMENTAL: With Sam Epstein and John Goodman in his latest movie [COLUMBIA PICTURES]

George Clooney is a most enigmatic film star. He goes on chat shows, attends red carpet events and gives interviews. He talks, he appears to share insights and yet we still don't know what he really thinks.

More than any of his peers he has perfected the art of faux familiarity. He uses charm and humour to create the impression of candour, even intimacy, but also to mask his true feelings. It is a skilful way of handling fame.

"People don't want to hear me complain so I don't," says Clooney with an awareness that is rare in a profession rife with self-absorption. Instead he jokes - about himself, about his friend Brad Pitt ("I don't like him") or his recent co-star in Gravity, Sandra Bullock ("She drinks a little too much and falls down a lot").

But if not himself Clooney does take his work seriously. He has had an exceptionally busy year. As well as the Bafta-nominated Gravity (with Bullock) he has produced August: Osage County, starring Meryl Streep and Julia Roberts and written, produced, directed and starred in his latest film The Monuments Men about an army platoon in the Second World War who go around rescuing works of art that have been stolen by the Nazis.

Now 52 he is at the peak of his career, which has already outlasted several of his contemporaries. Tom Cruise is no longer the force he was and even buddy Pitt seems to be on the slide if the abysmal World War Z is any indication.

Clooney has won two Oscars - for Best Supporting Actor in Syriana and as producer of the 2013 Best Picture winner Argo - and is the only person to be nominated for Academy Awards in six different categories.

He has made duds too (Batman And Robin, Intolerable Cruelty, Solaris) yet his lustre remains untarnished, just as his greying hair remains undyed and the tramlines on his forehead un-botoxed.

"Luckily it became obvious pretty early on that I was not destined to be an action star so I don't have to worry so much about how I look," he says. "I hear all this talk about how grey I am getting but I can't imagine ever dyeing my hair. My dad has this full head of white hair and I think it looks pretty good."

So do legions of women all over the world. Clooney is one of only three men to have been voted People magazine's Sexiest Man Alive twice. Yet he remains resolutely unattainable - at least for longer than a year or two.

After his marriage to Talia Balsam (daughter of actor Martin Balsam) ended in divorce in 1993 after four years he swore he would never marry again but that hasn't stopped any of his many female companions from trying to change his mind.

The list of comely ladies he has squired over the years would fill several little black books. It includes actresses Kelly Preston (now Mrs John Travolta) and Renée Zellweger, British model-turned radio DJ Lisa Snowdon and Italian starlet Elisabetta Canalis.

His most recent girlfriend is former professional wrestler Stacy Keibler but they split last summer. "This fascination with my love life is really something," he says. "I keep saying I'll never get married again or have children but people just don't want to believe me."

Perhaps that's because on another occasion he said: "I think it's the most responsible thing you can do, to have kids. It's not something to be taken lightly. I don't have that gene that people have to replicate. But everything in my life has changed over time."

I love my life as it is. I realise that the worries I have are trivial

Should a radical shift in his views occur the public is unlikely to learn about it from social media. Clooney is no fan of Twitter, Facebook, Instagram et al. He is not even that keen on emails.

"Those [social media] allow you to sound off without really thinking about what you are saying. That would get me in a lot of trouble. I don't for the life of me understand why any famous person would ever be on Twitter because you're going to be available to everybody.

"So one drunken night you come home and you've had two too many drinks and you're watching TV and somebody p***** you off and you fight back. And you go to sleep and you wake up in the morning and your career is over.

"I've learned it is better to send a letter than an email if you want to keep things private. There is something about putting pen to paper that really makes you think."

Whether it is former vice-president Al Gore or ex-UN secretary-general Kofi Annan guests who stay at his Italian holiday home on Lake Como have to abide by certain rules. "I really want the people that come there to enjoy themselves. That is why I have this rule about no phones. The world does not need to see pictures of me on vacation."

He saw the effects of celebrity at close quarters in his aunt, the singer and actress Rosemary Clooney. "I had my aunt Rosie who was famous and then not, so I got a lesson in fame early on and I understood how little it has to do with you. And also how you could use it."

Yet despite that early lesson and all his precautions and his own ability to deflect intrusive questions, he still thinks he should manage his own celebrity better.

"For me, Brad Pitt is doing it right. He has this whole side of himself that we know nothing about. You have to do that to survive in this business, keep parts of your life just for yourself."

It also helps that Clooney was already 33 when he first shot to fame as Dr Doug Ross in the long-running TV series ER, and that there is someone around to, as he puts it "tell you what's what".

That role is filled by his father. Nick Clooney is a highly respected former news anchorman and one suspects the guardian of his son's political conscience.

When George was branded a traitor for opposing the war in Iraq he called his father for advice. Nick replied, "Grow up. You've got a job. You've got money. You can't demand freedom of speech and then say 'But don't say bad things about me'. That's not how it works."

George took his father with him when he went to Sudan and Chad to make the documentary A Journey To Darfur. During 10 days there they were held up by boy soldiers toting Kalashnikovs.

When George was invited to address the UN Security Council on Darfur, his father urged him to accept "because you're the liberal who's going to chastise the UN".

These days he says he prefers to be "a little more low key" in his activism - not because he fears damaging his film career but more the other way round.

"I do know that my movie career hurt my father's political career. When he ran for Congress his opponent made the campaign all about me. My dad lost but says he has no regrets. All of us need to get involved however we can."

As well as the Lake Como villa Clooney also has a house in Cabo, Mexico, where his neighbours are Leonardo DiCaprio, Cindy Crawford and her husband Rande Gerber, but his main home on the less salubrious side of the Hollywood Hills is an unpretentious Tudor-style house one guest described as "a man-cave writ large".

In an interview with the Hollywood Reporter he admitted being unable to fall asleep without the TV on and also to being cheated on and dumped by women. "I have been infinitely more alone in a bad relationship. There's nothing more isolating."

His only full-time housemate now is Einstein, a black cocker spaniel. "I love my life as it is," he says. "I realise whatever worries I have are trivial in comparison to those of many people. I have learned not to be swayed by the attention.

"It doesn't matter what people I don't know have to say about me. What matters is what my friends and family think of me and so far they are all returning my calls."